14 DAY TRIAL // An interesting set of climate extremes was recorded in North American throughout December 2013, according to data compiled by NASA satellites. While the Arctic heated up to record-breaking levels for this month, the continental United States experienced abnormally-cold temperatures.
Climatologists say that the main reason for this discrepancy is the polar jet stream in the northern hemisphere, which forced masses of very cold air to move south from the North Pole, while warm air was redirected northwards.
The stream can exhibit variations called Rossby waves, but the ones recorded this December exceeded standard deviations. In northern Alaska, at Deadhorse Airport, temperatures reached 4 degrees Celsius (39 °F) on December 7, the warmest temperature recorded at this location since 1968.
The image above is a map of land surface temperature anomalies recorded for the week of December 3-10 in North America, compiled from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the NASA Terra satellite.